MATLAB is an abbreviation for "matrix laboratory."
All MATLAB variables are multidimensional arrays, no matter what type of
data. A matrix is a two-dimensional array often used for linear algebra.
a = [1 2 3; 4 5 6; 7 8 10]
a =
1 2 3
4 5 6
7 8 10
Without semicolon, display the data items.
Another way to create a matrix is to use a function, such as ones, zeros, or
rand. For example, create a 5-by-1 column vector of zeros.
z = zeros(5,1)
z =
0
0
0
0
0
format long
To perform element-wise multiplication rather than matrix multiplication,
use the .* operator:
p = a.*a
The matrix operators for multiplication, division, and power each have a
corresponding array operator that operates element-wise.
a.^3
Array indexing
a(2, :)
ans =
4 5 6
a(2, 3)
ans =
6
a(2)
a(1:3,2)
myText = 'Hello, world';
disp('hello world');
clc
The clc function clears the Command Window.
x = 0:pi/100:2*pi;
y = sin(x);
plot(x,y)
xlabel('x')
ylabel('sin(x)')
title('Plot of the Sine Function')
To add plots to an existing figure, use hold.
%x = 0:pi/100:2*pi;
x = linspace(0, 2*pi, 100);
y = sin(x);
plot(x,y, 'b--o');
hold on
y2 = cos(x);
plot(x,y2,'r^')
legend('sin','cos')
grid;
xlabel('x')
ylabel('sin(x) and cos(x)')
title('Plot of the sin and cos functions');
% Means comments in Matlab programs % meshgrid function generates x and y coordinates for a 2D grid [X,Y] = meshgrid(-2:.2:2); Z = X .* exp(-X.^2 - Y.^2); surf(X,Y,Z)
% subplot function divides a figure into multiple areas so multiple plots appear on the same figure.
t = 0:pi/10:2*pi;
[X,Y,Z] = cylinder(4*cos(t));
subplot(2,2,1); mesh(X); title('X');
subplot(2,2,2); mesh(Y); title('Y');
subplot(2,2,3); mesh(Z); title('Z');
subplot(2,2,4); mesh(X,Y,Z); title('X,Y,Z');
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